Blocked heater matrix?

[Mountain]

Aside from my miriad of leaks, I've never managed to get anything other than warm air from the heater. This is even on one of those 'without a leak' days after careful bleeding.

Now I have always suspected a blockage or restriction in the front heater matrix as after all those replaced hoses and re-bleeds there surely has to be at least a blast of hot air during bleeding.

Lo and behold! The other day I was in the supermarket car park driving along and I did my habitual......lets see if the heaters blowing 'warmish' air still. Well, this distracted me from the approaching speedbump and I bounced over it a little too fast.

BUT guess what? After I'd bounced over the bump I got a blast of nice hot air

I think the bump dislodged something that was partially clogging the matrix. I don't think it was an airlock.

I have since replaced 2 more hoses and re-bled.
Now the the bleeding procedure is spot on.
Bubbles end, stat opens, heater hot. Job done.

Also, I am now officially leakless. I have driven around for miles today. Temp stays pretty constant, heater stays hot.
I have to say the Bongo is driving really well now.

I'm still going to get all those outstanding hoses replaced when they arrive, but for the timebeing I think I'm eventually driving a normal Bongo

[321Away]

possibly not blocked, part of the bleeding procedure i always carry out is to remove air intake and pull off pipes to the front matrix as if you drain the system right down,there always seems to be an airlock in the front matrix, we flush every car that comes through here and the top matrix air locks more often that not and the rest of the system works fine but no warm air form the front heater but still from the back!
Julian

[mikeonb4c]

possibly not blocked, part of the bleeding procedure i always carry out is to remove air intake and pull off pipes to the front matrix as if you drain the system right down,there always seems to be an airlock in the front matrix, we flush every car that comes through here and the top matrix air locks more often that not and the rest of the system works fine but no warm air form the front heater but still from the back!
Julian

How refreshing it is to have posts from a professional who has seen many Bongos. There's an awful lot of heated speculation (no pun intended ) on here based on guesstimates and hypothesis, so your post is like a breath of fresh air. Thank you Julian.

[Mountain]

Hi Julian,

Thanks for the advice .
Unfortunately I'm not a Bongo expert but have had no choice to attempt some hose changes myself due to finances....or lack of.

Some of the hoses have been horrendously furred up with rust. The top rad hose to the header tank was almost blocked at the bend near the header tank. I stuck a screwdriver down it and gauged out loads of rusty gunk. (I do tend to think the 'full engine service' my Bongo had before I bought it, consisted of it being topped up with incompatible antifreeze on top of the Japanese stuff sat in it?)

Excuse me if I'm being a bit thick, but if you've taken the heater hoses off don't you risk introducing air when you put them back on?
Also, if there is a stubborn airlock in the front heater matrix what is the best way to shift it? Especially when following the bleeding procedure doesn't.

Any help greatly appreciated, because I'm almost at the point of cutting my losses and giving up altogether.

[Mountain]

Well, looks like I spoke too soon

Just been for another drive.
The modified temp gauge varies between about 10 'O' clock and 1 'O' clock.
My extra gauge with the temp sensor on the top rad hose varies between 70 and 80C when warmed up.

So at least it's not overheating.

BUT.

The heater is wavering between hot and warm.

Any ideas?

I'm utterly depressed. I just can't throw any more money at this, it has literally bankrupted me. I have no confidence in it at all.

[jaylee]

lets see if the heaters blowing 'warmish' air still. Well, this distracted me from the approaching speedbump and I bounced over it a little too fast.

BUT guess what? After I'd bounced over the bump I got a blast of nice hot air

I think the bump dislodged something that was partially clogging the matrix. I don't think it was an airlock.

Well, looks like I spoke too soon

Just been for another drive.
The modified temp gauge varies between about 10 'O' clock and 1 'O' clock.
My extra gauge with the temp sensor on the top rad hose varies between 70 and 80C when warmed up.

So at least it's not overheating.

BUT.

The heater is wavering between hot and warm.

Any ideas?

I'm utterly depressed. I just can't throw any more money at this, it has literally bankrupted me. I have no confidence in it at all.

Based on what i've read..? Could you have a loose (or sticky) airflow direction flap in yer heater duct thingy??? http://www.lushprojects.com/bongopartsm ... mgno=.html

[missfixit70]

try bypassing the front heater matrix, connect the inlet & outlet together, or even try backflushing it? from all the issues you've had, I'd be surprised if it wasn't blocked TBH, it's got very fine waterways if it's anything like the rear one.
Have you pressure tested the system? I reckon you're still getting air in somewhere.

[Mountain]

Oh! I hope so......

I'll go and have a look. Do you know which is the 'temp flap'?

[Mountain]

try bypassing the front heater matrix, connect the inlet & outlet together, or even try backflushing it? from all the issues you've had, I'd be surprised if it wasn't blocked TBH, it's got very fine waterways if it's anything like the rear one.
Have you pressure tested the system? I reckon you're still getting air in somewhere.

Not pressure tested since the head gasket was done.

I've also noticed the front two hoses to the heater are not 'proper' ones. The bottom header tank one is also not shaped. This may be effecting the heater flow?

I can't risk driving if there is air getting in, and it will be at least 10 days before the last outstanding hoses arrive.
So...back to 5-6hours public transport a day until the hoses arrive